Continuous aim gunfire control system



Sept 27, 1932.. J. DUGAN CONTINUOUS AIM GUNFIRE CONTROL SYSTEM Filed May25, 1932 SShQG'LS-Sheet l Sept. 27, J. DUGAN 1,880,174

CONTINUOUS AIM GUNFIRE CONTROL SYSTEM Filed May 25, 1932 5 ShetS-Sheet PSept. 27, 1932. J, DIUGAN @$80,174

CONTINUOUS AIM GUNFIRE CONTROL `SYSTEM Filed May 25, 1932 5 Sheets-Sheet5 Sept. Z7, 1932. J. DUGAN CONTINUOUS AIM GUNFIRE CONTROL SYSTEM I 5sheets-sheet 4 Filed May 25, 1932 sepa. 27, 1932. J, DUGAN www@CONTINUOUS AIM GUNFIRE CONTROL SYSTEM Filed May 25. 1932 5 sheets-sheet5 Patented Sept. 27, l32

JOSEPH DUGAN, F LOS ANGELES, CALIFORNIA CONTINUOUS AIM G'UNFIE CONTROLSYSTEM Application led May 25, 1932. Serial No. 613,489.

The invention forming the subject matter of this application is a firecontrol system adapted for use on unstable platforms such as the deck ofbattleships, the chassis ofwrailroad guns, tanks, etc. to eliminate theeffect of roll and pitch of the platform on the train and elevationsettings of the gun or guns mounted on such platforms to rotate about.the usual train and elevation axes.

The 'object of the present invention is to provide such guns withcontrol mechanism for maintaining the guns continuously core rected intrain and' elevation for the trunnion tilt error caused by rolling andpitching' of the platform, regardless of the position or movements ofthe target in space relative to the gun. A

Other objects of the invention will become apparent as the detaileddescription thereof proceeds. I

In the drawings Figures l, 2, 3 and et are mathematicaldiagramsexplanatory ofthe system involved in the present invention;

Figure 5 is a View, partly in side elevation and partly in centralvertical section, disclosing the arrangement of the essential elementsof the mechanism forming the gun director of this system;

Figure is an end elevation of the director shown in Figure 5, parts ofthe mechanism being broken away and shown in section to illustrate thedetails of construction;

Figure 7 is a horizontal section taken on a line 7 7 of Figure 5;

Figure v8 is a plan view of the corrector mechanism forming part of theaforesaid gun director, parts beingbroken away to show details ofconstruction;

Figure 9 is a fragmentary detail in elevation of part of the firecontrol elements of the director;

Figure l() is a wiring diagram illustrating the connection between thefollow-up motors forming part of the director and a two-part commutatorfor controlling said motor; and

Figure 11 is a diagram illustrating generally the Ytype of gun adaptedto be controlled by thedirector 'illustrated in Figures ed in Figures lto 4, inclusive; and the symbols used therein to designate the various'angles and their mutual relation have the mean-- ings attributed to themin the following table:

A-angle of elevation between a horizontal line, in the vertical plane ofsight to the target, and the line of sight;

cle-vertical angle of depression between a horizontal line, in thevertical plane of sight to the target, and the line of sight;

.s-vertical angle (super-elevation) between the line of sight and thebore axis of the gun;

angle of elevation of the gun relative to the horizontal in the verticalplane of sight to the target;

P-vertical angle of the deck to the horizontal in the vertical plane ofsight to the target;

R-angle of roll of the deck in a plane per- 75 pendicular to the deckand perpendicular to the vertical plane of sight to the target at anyangle of pitch;

E-angle of elevation of the gun in the Vertical plane of sight to thetarget, relative to the deck and uncorrected for cross roll R;

Ec-angle of elevation of the gun in a plane perpendicular to the deckcorrected for cross roll R;

T-'angle of correction of the gun in train in the plane of the deck fromthe vertical plne of sight to the target, to correct for error due tocross roll of the deck through the angle R;

Dg-angle of lateral deflection of the gun bore axis relative to thevertical plane of sight to the target;

D-angle of lateral deflection of the vertical plane containing the boreaxis ofthe gun and set-ofi1 in a horizontal plane relative to thevertical plane of sight to the target;

DZ-angle of deiiection of the gun in the plane of the deck relative tothe vertical plane of sight to the target.

In this system the terms pitch and roll have broader meanings than areapplied to them in seamans language. The axis of roll lies constantly ina plane parallel to the gun deck and in the vertical plane of sight tothe target passing through the intersection of the train and elevationaxes of the gun, regardless of the pitch .of the deck in the plane ofsight, and regardless of any lateral deflection of the gun relative tothe vertical plane of sight to the target. l

The expression vertical plane of sight is used for convenience inreferring to the vertical plane passing throu h the target and the pointof intersection o the train and elevation axesof the gun. It iscontemplatedv that the guns controlled by this director system may befiredat targets invisible to per-- sons operating the guns; as forexample, at targets obscured by a smoke screen or by a mountain range,etc. In this case, it would be necessary to set the director and theguns by compass, by sighting at some object known to lie in the verticalplane through the target and the intersection of the gun axis, or bysome other means of determining the direction of the target from the gunor guns.

The diagram shown in Fig. l is intended to illustrate the necessity forconsidering the angles of altitude and depression of the target relativeto a horizontal line in the vertical plane of sight, in order todetermine the angle e of elevation of the gun bore axis relative to thesaid horizontal line. As shown in Figure 1, the horizontal line 0T2 istaken as the horizontal line of reference in the vertical plane of sightto the target, and the distance 0T2 is considered as the maximumhorizontal range of a gun positioned at the point O and elevated so thatthe trajectory of a shell tired therefrom will pass through the tar etT2. It will be evident :from Figure l, that t e altitude A of the targetT2 above the horizontal line is zero. It will also be evident that thelangle e indicates the angle which the bore axis of the gun makes withthe said horizontal line of reference. 'In this case theangle e is equalto the angle of the superelevation S2. v

The same angle of gun elevation e relative to the horizontal would benecessary in firing at targets T1, T3, and T4 lying on the trajectory ofthe gun positioned at the point O and elevated for maximum range. Thetarget T1 is evidently depressed below the horizontal reference linethrough the angle de while the line lire or angle e remains the same asbefore. In this case, it is evident that the superelevation angle isequal to S1.

In the case of the target T3, the altitude is A3 while the angle ofsuperelevation is S3. Similarly the angle of superelevation of the gunaimed atl the target T4`is the angle S4, nd the altitude of the targetof the angle It is evident., then, that it is necessary to take int'oconsideration the altitude or depression of the target relative to thehorizontal line of reference in the Vertical plane of sight tothe targetin order to determine the line'of'ire ofthe gun; that is, to determinethe angle of 4elevation e of the gun bore axis relative to the saidhorizontal reference line. The target T5 is illustrated in Figure 1 aslocated at the same range from the gun as the target T4; but the targetT5 lies in the horizontal plane and the trajectory for target T5 isdifferent from the trajectory for target T4 and much less curved and adilierent angle of gun elevation relative to the horizontal line isrequired. The angle of gun elevation for target T5 would also berequired for any target lyin in the trajectory of target T5 as, forexamp e, the target T6 lying in the 'line of sight depressed throughdepression angle De in the vertical plane of sight to the target.

This discussion of the matter illustrated in Figure 1 is interpolatedhere to emphasize the. fact that although the altitude angle may bedetermined from the stabilizedv sight forming a part of the directordisclosed herein, it is not'essential to use the director sight for thispurpose. The angle of altitude is usually determined by an altimeterconnectedA with the range finder. The angle of superelevation must bedetermined in connection with the angles of altitude or depressionbefore it can be introduced into any corrector system. f

The angle e includes all angles measured in the vertical plane of sightrelative the horizontal in that plane. This, of course, includesaltitude, sight depression, vertical prediction and ballistic correctionangles, etc.; and constitutes one of two settings of an ideal gun,forming part of this system, relative to a plane representing thehorizontal plane of reference. The algebraic sum of this an le e and thepitch angle P, give the setting of the ideal gun relative to the deck,and in the vertical plane of sight to the target.

Figures 2, 3 and 4 are vector diagrams in which the vectors designatedby the characters E, Ec, T and Dg are to be considered as segments ofarcs of great circles lying on a sphere having its center at the point Oin each diagram. These vectors represent elements in the corrector partof the director disclosed herein and the vectors corresponding to saidelements are designated by similar reference numerals underscored.

Figure 2 is a vector diagram of a general type in which deection of thetarget from a i vertical reference plane is taken into consideration.The director mechanism includes a Amechanical replica of the vectordiagram ICL! man@

fill

assuma the angles Ec and T when the angle E and g are given. In'accordance with the laws of spherical trigonometry: f

(a) sin Dg=sin K sin m; or, 4sin =sin Dg/sinK (b) tan E=tan K cos or,cos m=tan E/tan K l' (c) tan r=tan Dg/sin E; or, -cos aar-*sin E/tan Dgtan T= tan K(cos 90- (R4-ad) tan K sin (Rl-x) sin Ec sin KsinGlO- (R4-a)sin K cos (R4-x) sin K(cos R cos msin R sin x) sin Dg sin a:

cos R cos xsin K sin Dg msm R sin Dg cos R cot xsin Dg sin R D RilLl sing cos mn Dg sin Dg sin R sin Ec sin E cos Dg cos .R 4

sin Dg sin R Equations (a), (b) and (c) are fundamental equations usediii spherical. trip;- onometry, the solutions of which are obvious frominspection of the diagram in Figure 2; and are employed herein merely tofacilitate the solution of thc more complicated equations (l) and (2).

Figure l is a vector triangle in which the deflection angle Dg -is zero.It Will be evident from inspection of Figure 4, that the Atangent of theangle .of train 'correction T of the giin. This will also be evidentfrom consideration of Figure 4 in which it is evident that if thearcuate line representing the dock be rolled abeiit the point ab in theIline gun is elevated above' the decir.

ings, it Willbe necessary to trans below the horizontal plane give.

oab, no vector triangle will be generated. lt is furtherevident that ifthe gun he depressed toward the deck, instead of elevated, thevectortrian'gle representing'this nondition will be above the point abin l and to the right of the vertical plane VOf; the train and elevations being eiiected in the opp tions to the corrections necessarendition will also be evident from consideration of any o' the equations(l), (2), (8) and (fl) in which a negative angle E would give negativeresults for the angle T, i

In determining the angle of use in this system, and reterri ticularly toFigures 2 and 3 i tlection angle Dg of this line r plane perpendicularto the vertic reference VULZ from its elevated p the horizontal plane.The method. of performing this translation is clearly indicated inFigure 3, in which the angle D indicates the angle of deection in thehorizontal plane of reference. This angle l) the projection on thehorizon sition Where the gun boreaxis in sphere. A continuation of thisof deflection Dal in the plane o.; ne deck Which is clearly shown in thedrawing as depressed through the angle P belori7 the horizontalreference plane..

Regardless of the position of the angie Dg either above or belowthe'horizc l plane, it is necessary that its projecti horizontal planebe determine can be set in properly in the de.1 of the apparatus. Fortargets lyi same horizontal plane as the gn vious that the deflectionangle l?" ,J determined in the usual mannerv It` will be apparent fromthe foregoing discussion, that the-system is intended to correctcontinuously the errors diie te vthe roll and pitch of the deck, and toprovide a means for setting the gun in train and elf-va''icn as if thedirector and gun were nie n stable horizontal deck or platform., alsobeevident that the systeiii is dif-:signed to divorce the problem oftrunnion tilt correction from the line of sight; to con- Sider thisproblem With reference to vertical 4 and -horizontal planes, regardlessof the elevation or depression of the sight.

In Figures 2, 8 and 4,' the vertical `1eference plane is indicated .bythe sector VUOZ; and Of indicates the horizontal reference line lying insaid vertical plane. The are @nl is the angle of train correction Trequired to compensate for the error in gun train caused by the roll ofthe deck through. the angle R about the axis l/*BJ lying in the plane of`tions; and the arc ab is the angle of lateral deflection Dg of the gunbore axis to comof the shell, etc. The arc ad is the angle ofpensate forerrors due to drift, change of position of the target during the time ofHight elevation E of the un relativeto the deck,uncorrected for rollaout the axis R-R.

As shown in Figures 5 to 10 of the drawings, the director comprises apedestal 1, having a training table 2 mounted to rotate thereon about atrain axis X-X perpendicular to the unstable gun4 deck or platform.Standards 3 and 4 are secured to the table 2, on opposite sides of theaxis X-X and at substantially equal distances therefrom.

A gimbal ring 5 is pivoted to swing in said standards 3 and 4 about thecommon axis of the trunnions 6 and 7; and an inner g'inibal ring 8 ispivoted to ring 5 by trunnions 9 and 10 having their common axisintersecting the axis of trunnions 6 and 7 at right angles. The ring 8is channel shaped 1n cross section. A ring, or spider 12 is mounted torotate in the channel 11 of ring 8; and hassuitably secured thereto anarcuate bar 13 provided with a guide groove 14 for slidably receiving anantifriction wheel 15 at the end of a cylindrical rod 16 the axis ofwhich represents the axis of an ideal gun. A

The bar 13 is perpendicular to ring 12 and iS braced in this position bylthe side bars17 and 18 secured at their lower ends to the said innerring 12.

The ideal gun comprises a gear ring "19 rotatably mounted in an arcuatecasing 20 supported by standards 21 and 22 on a deflection plate 23mounted on the table 2 to rotate about the train axis X-X. TheA gearring 19 is rotated about its center by means of the worm 24 secured to ashaft 25 journaled in the standards 26 and 27 also secured to thedeflection plate 23 between the standards 2l and 22.

The rod 16 passes rotatably through an aperture -28 in the gear ring 19,and is connected at its inner end to an arcuate bar 29 having secured toits opposite ends the trunnions 30 and 31, representing the trunnionsofthe real gun. The trunnion 30 is journaled in the ring 12; and thetrunnion 31 is connect'ed to or forms a. part of the rotor` of elevationtransmitter E-T which has its stator fixed to the ring 12. The trunnions30 and 31 have their common axis lying in the plane of the intersectingaxes of the trunnions 6, 7, 9 and 10.

The channel ring 8.has arms 32 'and 33 extending from its'lower faceinwardly to form a cup.; shaped support 34 for an electrical ydifferential 35 of the Well known selsyn to table 2. A clamping nut 43threaded onA stud 40 operates to clamp arm 38 in any desired position onbracket`42.

The ring 5 at its rear end has chisel edge electrical contact member 44suitably secured thereto and insulated therefrom. rlhis member 44extends around the ring 5' for twenty or'thirty degrees on oppositesides of the axls of the trunnion 10. The edge of member 44 .is designedto make contact with a. contact 45 secured to a screwthreaded stud 46which is mounted to slide in a slot 47 formed 1n an arcuate fire controlscale member 48.

The member 48 is struck from the center of ring 5; and terminates at itslower end in a spacer block 49'separating the 'standards 50 and 51 (seeFigure 9) to the deection Y. plate 23. The shaft extends through anaperture in the bloeit 49 and terminates ina crank handle 52. gun.elevation scale plate 53 is fixed to shaft 25 to read against anindicator 54 secured. to. block 49. clamp nut 55 serves to4 adjust andhold the contact 45 in any desired angular position on the arcuatemember 48.

The trunnion 6 has a 'bevel gear 56 secured to the end thereofprojecting through standard 3; and, this gear 56 mesh-es with a. similargear 57 secured to the rotor shaft 58 of a follow-up motor 59 which is;secured to the side of standard 3. The trunnion 9 extending from ring 8through ring 5 has a bevel gear 60 secured thereto; and this gear 60meshes with a similar gear 61 fixed to a shaft 62 journaled in a bearingbracket 62 fixed to or 'formed integral with the ring 5.

The shaft 58 is connected by a universal joint 63 to the slottedcylindrical. member 64, having another member mounted to slidenon-rotatably therein. The two finembers 64 and 65 constitute atelescoping shaft, and are the direction finder element of the director.

The shaft 69 has its free end fixed to a. bevel gear 72 meshing with asimilar gear 7 3 fixed to a trunnion 74 extending through gimbal ring71.

The shaft 62 (see Figure 5) is connected by a universal joint 75 to amember 76 slidably but non-rotatably mounted in a cylindrical IOL member77 which is, in turn, connected by a i universal -joint 78 to shaft 79of a follow-up motor '80.1 A key 81 fixed `to member 76 slides in theslot 82 of member 77 to prevent relative rotation of members 76 and 77.The follow-up motor is suitably bolted to the standard 83 which, withstandard 84, forms the means for pivotally supporting the gimbal ring7l. Trunnions 85 and 86 extend from the ring 75 through suitablebearings in said standards 83 and 84 in the usual gimbal ringconstruction. The trunnion 85 has a bevel gear 87 secured thereto andmeshing with a similar bevel gear 88 fixed to the end of the follow-upmotor shaft 79.

A trunnion 89 cooperates with trunnion 74 in pivotally connecting theintermediate gimbal ring 90 to the ring 71. Trunnions 91 and 92pivotally connect another inner gimbal ring 9.3 to the ring 90; andtrunnions 9e and 95 serve to support the gyro 96 rotatably in the saidgimbal ring 93.

A two part commutator 97 fixed to the inner ring 90, cooperates with aconduct-ing wheel 98 rotatably mounted on the lower end of an arm 99 tocontrol the operation of the follow-up motor 80 in the well knownmanner. The arm 99 is fixed to the trunnion 91, and is rotated Jthereby.A two part commutator 100 is fixed to the ring 93 to cooperate with aconducting trolley wheel 101, 4rotatably mounted on the lower end of anarm 102 depending from and fixed to the trunnion 95, in

controlling the operation of the follow-up motor 59 in the correctorpart of the director.

Yhere is nothing novel. in these followup mechanisms, Ithe wiringconnections of which are shown diagrammatica-lly in Figure 10.

'lfhe target sights 10B-1041 are mounted on a 'trunnion member 105pivoted at its opposite ends .in the sight standards 106 and 107 carriedby the intermediate gimbal ring 90. Spirit levels 108a-nd 109 aremounted on the ring 90 for use in checking up the movements of the gyro,and to lindicate the corrections necessary to 'restore the ring 90 tohorizontal position when moved therefrom either by wandering of the gyroor other cause.

Any suitable levelling sight L and cross levelling horizon sight CL 'maybe suitably supported on the vring 90 to serve the same purpose as thespirit levels 108 and 109 whencvcr it is possible to sight on thehorizon or distant objects. The ring' 93 and gyro 96 may bereplaced by aweight suitably fixed to the ring 90. The absolutely essential require-lment in this system is the maintenance of the ring 90 horizontal in thedirection of the axis of trunnions 85 and 86 and also in the directionof the axis of trunnions 74 and 89. l/Vhether this be effected by acommon pendulum,. ajgyroscopic pendulum, horizon sights,

or spirit levels,or all of these well known levelling devices isimmaterial so far as the principle of this invention is concerned.

Figure 11' illustrates diagrammatically the type of gun adaptedto becontrolled by the director system disclosed herein. The gun 110 ismounted by its trunnions 111 112 to rotate about its elevation axis inthe stand ards 113 and 114 extending up from the training table 115.

The table 115 is mounted to rotate on the support 116 suitably securedto the deck or unstable platform. A repeater 'llBL repeats the movementsof the director train transmitter T-T modified., when necessary, byoperation of the electrical dierential trans former 35. A follow-upmotor Tlf. may be controlled by this repeater T-R to rai the table 115through gearing 117 118 c 'meeted respectively to the rotor shaft of' 5eter T-M and the table 115.

The gun may be rotated in elevation by gearing 119, 120 connecting thegunt-o the shaft of a follow-up motor E-li/i un` r the control of theelevation repeater E is electrically connected to the elev. mitter E-Tof the director. lThe den follow-up mechanism are merely inc thedrawing, since the invention cerned with any particular mecha trainingor elevating the gun. Ai well known follow-the-pointer. ing or follow-uptrain and elev anisms may be used to control the and train movements ofthe gun or The train transmitter is connecte cally through wiringindicated g -the reference numeral 121 to ti transformer 35; and wiring122 c sclsyn7 transformer 35 to the tran T-R at the gun. rll`his trainrepeateia follow-up train motor 'iT-M through I ing 123 to operate the.gearing 117 18 or rotating the gun in train. A two-part comm mutator(not shown) is fixed to the gear 121 of the train repeater and a pointer125 rotatably over this commutator operates control the direction ofrotation of the shaft of the follow-up motor T-M. This method offollow-up control is old and well. known in the art and is quite similarto that illustrated in Figure 10 of the drawings. The elevationcorrection Ec is transmitted from the elevation transmitter ET throughthe wiring 124-. to the elevation repeater E-R at the gun. The elevationrepeater controls .a follow-up motor E-M in the usual manner to operatethe elevationgearing 1197 119 and 120 and rotate the gun 110 inelevation aboutits trunnion axes 111 and 112.

The invention is not concerned with any particular wiring system and adirect cur.-

rent system of transmission may be used intion as is performed by therepeater R-33and transmitter T-4, in my 4United States Patent No.1,733,531. A single transmitter may be substituted for the transformer35, and 5 the train transmitter may transmit the change of bearing ofthe target directly to the train repeater at the gun. In this case,however, it will be necessary to interpose a diiferential between the.transmitter substituted for the transformer 35 in order that the traincorrection may be added algebra-l ically to the train correction causedby change of bearing between the gun and target transmitted to the trainrepeater through the same diiferential.

The corrector mechanism shown in Figures 5 and 6 operatesas amechanicalcomputer to solve the Equations (l), (2), (3) and (4) and maybe used separately from any particular direction finder to determine thecorrections necessary to eliminate trunnion tilt errors in any gun ofthe type shown in Figure 11 and mounted on anunstable platform.

The elements of the corrector mechanism corresponding to the vectorsshown in Figures 2 and 4 have the same reference numerals as thesevectors but without underscoring. For example, the arcuate member,13,shown in Figures 5 and 6 corresponds to the vector E- indicated inFigures 2, 3 and 4 by the reference numeral 13. The axis of roll RR inthe vector diagramsis duplicated in the corrector by the common axis9-10 of the trunnions 9 and 10. The gimbal ring 5 in the correctormechanism is represented in Figures 2, 3 and 4 by the arcuate line 5;and the gimbal ring 8 is represented in the vector diagrams by thenumeral 8. The vector Ec ofthe vector diagrams 2, 3 and 4 representsthe' position of the member 13 of the corrector after the ring 5 hasbeen pitched downwardly fromthe horizontal through the angle P, andafter the ring 8 has been rotated about the axis of trunnions 9 and 10through the angle R.

It Will' be seen from comparison of the vector diagrams with themechanism illus- -f trated in Figures 5 and 6 of the drawing, that themember 13 ,rotates` about the axis lof rod 16 in the same manner as thevector E0 rotates about the point b in Figures 2 or 3, and about thepoint ab indicated' in Figure 4, and that the member 13 or vector Eccoincides with the intersection of the axis of the roller 15 with thecenter line of the member 13. The ring 5 rotates about the gun axis ofthe trunnions 6 and 7, which is indicated in Figure 4 by a line to whichthe numeral 6-7 is applied. It will be,\apparent from comparison ofFigures 2, 3 and 4 with the other Iigures of the drawing that thecorrector showninthese other figures is a. mechanical replica 05 of thevectors shown in Figures 2, 3 and 4,

`tem composed of the rings this point of rotation of and that thiscorrector will solve with mathematical accuracy all the problems oftrunnion tilt correction which may bp represented by vectors, asillustrated in the drawings.

The fire control mechanism illustrated in Figures 5, 8 and 9 is ofpeculiar importance in this system inasmuch as the contact 45 is movedlaterally along with the deflection table 23 so that it can'be set alongthe scale 125 to control the angle of elevation in the vertical plane offire at which the gun may be red. Since the contact 45 moves lateral# lyaround the gimbal ring 5, it is necessary that the cooperating contact44 on the ring 5 be extended around said ring on opposite sides of thetrunnion axis 10, in order that the contact may be made with contact 45to control the instant of fire at any deflection setting of the gun.

It will be observed that the'various arcuate members of the correctormechanism are really segments of skeleton spheres having their center atthe center of the gimbal sys- 5 and 8 supported upon the standards' and4. The sight or direction finding part of the system is supported uponframe work 2 rigidly connected with the training table 2 and parallel tosaid table. It is not essential that the corrector part of the directorbe mounted so that the train and elevation axes of the ideal gun beperpendicular and parallel, respectively, to the deck: The corrector isin .reality a computer which may be located in any position in space solong as the pitch and cross roll of the gun platform are properlyapplied to the respective axes 6 7, 9-10 in the corrector. The correctormay be` placed side by side with the direction finding parts of thedirector, connected in tandem therewith, or located at a distancetherefrom and operated by any suitable type of electricaltransmission-z- From 'a mechanical. standpoint, it

1s most convenient to connect it to the direction finder as shown inthedrawings.

What I claim is: 1. An unstable platform, a sight, means or mountingsaid sight to pivot universally on said platform, a gun rota-table abouttrain and elevation axes on said platform, means for. simultaneouslydetermining the pitch of 'the platform in the vertical plane of sight tothe target and the roll of the platform in a plane perpendicular to saidplzuie of sight and perpendicular to said pl angles of pitch, means forini placements of the gun from te s d vertical plane of sight and from ahoi ital referen'ee plane, and mechanism operahie by both ros Of saidmeans for calculating and applying 2. Apparatus set forth in claim 1 incomf bination with means for determining the pitch of the platform inthe vertical plane of lire throughout all angular movements of theplatform and at any angle of angular displacement of the gun relative tothe vertical plane of sight.

3. In a 'lire control system; an unstable platform; a gun mounted torotate thereon about train and elevation axes; a director rolOtatablymounted on said platform to control andcorrect the movements of thegunabout said axes, and including means for simultaneously determining thepitch of the platform in the vertical plane of sight to theperpendicular to said vertical plane of sight and perpendicular to saidplatform at all angles of pitch, Aa computer, settable about mutuallyperpendicular axes and operably connected to said means, for solving theequations:

tan .T =tan E sin-R sin Ec=sin E cos R;

Where T is the angle of correction in gun train, E@ the correctedsetting in gun elevation, R the angle of cross roll, and E the angle ofelevation of the gun relativetothe platform uncorrected for cross rollR; and means for transmitting the computed angles T and Ec to the gun tocorrect the movements of the gun about said axes for pitch and roll ofthe platform.

4. In a lire control system; an unstable platform; a gun mounted torotate thereon about train and elevation axes; a director rotatablymounted on said platform to control and correct the movements ofthe gunabout said axes, and including means for simultaneously determining thepitch of the platform in the vertical plane of sight to the target andthe roll of the platform in a plane perpendicular to said vertical planeof sight and perpendicular to said platform at all angles of pitch, acomputer, settable about mutually perpendicular axes and operablyconnected to said means, for solving the equations: v

tan T=tan E sin R+ sec E tan Dg cos R' sin E0=sin E cos Dg cos R-sin Dgsin R;

Where T is the angle of correction in gunV train, Ec-the correctedsetting in gun elevation, R the angle of cross roll; E the elevation ofthe gun relative to the platform uncorrected for cross roll, and Dg theangle of llateral deflection of the gun bore axis relative to thevertical plane of sight to the target; and means for transmitting thecom` Clputed angles T and Ec to the gun to correct the movements ofthegun about said axes for pitch and roll of the platform. 5. A gun, Aaplatform on which the gun is adjustable about elevation and train axes55 which vary in angular position with variatarget and the roll of theplatform 1n a plane tions in the angular position of said platform; andmeans mounted to rotate on said platform about an axis Iixedperpendicular thereto and settable in planes parallel to said train andelevation axes and with reference v on which the gun is adjustable abouta set 0f relatively fixed mutually perpendicular axes which vary inangular position with variations in the angular position of saidplatform and means mounted to rotate about an axis fixed perpendicularto said platform and vadapted to have corrections applied ythereto inplanes parallel to said axes and with reference to horizontal andvertical planes, for automatically generating, from` said appliedcorrections, corrections inI the movements of the gun about sald axes,and for subsequently varying said generated corrections to compensate-themovements of the gun about said axes for changes in the angularpositions of said axes due to` angular movements of said platform.

7 A movable support, a sighting device and a gun, each rotatable on saidsupport about elevation and train axes; and means mounted to .rotate onsaid support about an axis perpendicular thereto and adapted to havecorrections applied thereto in planes parallel to said axes and `Withreference to vertical and horizontal planes, and'operated by and inaccondance with the movements of the said sighting device, forgenerating corrections in the movements of the gun about its said axesand for subsequently varying said generated corrections upon changes inthe angular position of said axes due to movement of the support.

v8. A movable support, a gun adjustable on said supportl about elevationand train axes varyingin angular position with variations in the angularposition of said support; and

means mounted to rotate on said/support about an axis perpendicularthereto and set# table in planes parallel to said axes and withreference to vertical and horizontal planes, to correct the movements ofthe gun about said axes, and' for generating theset correc-l tions interms of movements of the gun about said axes in their variouspositions, and for subsequently varying said generated corrections inresponse to and in proportions to changes inthe angular position of saidaxes due to movement of said support. i

9. -A gun, a mount on which the gun is ad! justable about elevation andtra-in' axes, a

member maintained on said mount in a predetermined angular position in.space independently of the insligiation of the elevation llO axis ofthe gun, a second member, means for angularly adjusting said secondmember relative to said mount in accordance with the range of the gun, adriving connection between said members whereby the first member isrotated, whilemaintaincd in said position in accordance with theinclination of the trunnion axis of the gun, and means for applying therotation of the first member to the train adjustment of the gun.

10. In a lire control system; an unstable platform; a' gun mounted torotate thereon about train and elevation axes; a direction finder; aninner gimbal ring supporting said f der, an outergimbal ring pivotallysupporting the inner ring, means for supporting the outer ring to rotateabout an axis parallel to said platform; a computer including a base, asecond pair of gimbal rings having the outer ring mounted to rotateabout an axis parallel to said base; means operated by maintaininghorizontal the inner ring of the finder during the roll and pitch of theplatform for transmitting4 the rotation of the inner ring of the finderdirectly to the outer ring of the computer and for transmitting therotation of the outer ring of the finder directly to the inner ring ofthe computer; and means cooperating with the rings of the computer andoperable by the rotation thereof for determining and transmitting, tothe gun, train and elevation settings corrected for roll and pitch ofthe platform.

11. In a fire control system; an unstable platform; a gun mounted torotate thereon about train and elevation axes; a director rotatablymounted on said platform to controland correct the movements of the gunaboutI said axes, and including means for simultaneously determining thepitch of the platform in the vertical plane of sight to the target andthe roll of the platform in a plane perpendicular to said vertical planeof sight and perpendicular to said platform at all angles of pitch, acomputer, settable about mutually perpendicular aXes and operablyconnected to said means, for solving the equation tan T=tan E sin R;Where T is the angle of correction in gun train, R is the angle of crossroll, and E the angle of elevation of the gun relative to the platformuncorrccted for cross roll; and means for transmitting the computedangle T to the gun to correct the movements of the gun about its trainaxis for pitch and roll of the platform.

12. In a fire control system; an unstable platform; a gun mounted torotate thereon about train andl elevation axes gva director rotatablymounted on said platform to control and correct the movements of the gunabout said axes, and including means for simultaneously determining thepitch of the platform in the vertical plane of sight to the target andthe roll of the platform in a plane perpendicular to said vertical planeof sight and perpendicular to said platform at all angles of pitch, acomputer, settableabout mutually perpendicular axes and operablyconnected to said means, for solving the equation sin Ec=sin E cos R;Where EC is the corrected setting in gun elevation, R the angle of crossroll, and E the angle of elevation of the gun relative to the platformuncorrected for cross roll; and means for transmitting the computedangle EC to the gun to correct the movements of the gun about itselevation axis for pitch and roll of the platform.

13. In a lire control system; an unstable platform; a gun mounted torotate thereon about train and elevation axes; a Vdirector rotatablymounted on said platform to control and correct the movements of the gunabout said axes, and including means for simultaneously determining thepitch of the platform in the vertical plane. of sight to the v targetand the roll of the platform in a plane perpendicular to said verticalplane of sight and perpendicular to said platform at all angles ofpitch, a computer, settable about mutually perpendicular axes andoperably connected to said means, for solving the equation: tan T=tan Esin R sec E tan Dg cos R; Where T is the angle of correction in guntrain, R the angle of cross roll, E the angle of elevation of the gunrelative to the platform uncorrected for cross roll, and Dg the angle oflateral deflection of the gun bore axis relative to the vertical planeof sight to the tar, get; and means for transmitting the computed angleT to the gun to correct the movements of the gun about its train axisfor pitch and roll of the platform.

14. In a fire control system; an unstable platform; a gun mounted torotate thereon about train and elevation axes; a director rotatablymounted on said platform to control and correct the movements of the gunabout said aXes, and including means for simultaneously determining thepitch of lthe platform in the vertical plane of sight to the target andthe roll of the vplatform in a plane perpendicular to said verticalplane of sight and perpendicular'to said' platform at all angles ofpitch, a computer, settable about mutually perpendicular axesr andoperably connected to said means, for solving the equation.:

sin Ec=sin E cos Dg cos R-sin Dg sin R;

Where Ec is the corrected setting in gun elevation, R the angle of crossroll, E the vangle of elevation of the gun relative to the platformuncorrected for cross roll, and Dg the angle of lateral deection of thegun bore axis relativetothe vertical plane of sight to the target; andmeans for transmitting the computed angle Ec to the gun to correct themovements of the gun about its elevation axis for pitch and roll o1 theplatform.

15. An unstable platform, a gun mounted to rotate thereon about theusual train and elevation axes, and a fire control director mounted torotate on said platform about an axis parallel to the train axis of thegun, said director including: means for determining the direction of atarget from the intersection of said train and elevation axes; and meansfor simultaneously determining the inclination of the platform to thehorizontal in the vertical plane through said intersection and target,and the inclination of the platform to the horizontal in the verticalplane of lire of the gun at all angles of deflection of the gun relativeto the first named plane. 1;, 16. An unstable platform, a gun mounted torotate thereon about the usual train and elevation axes, and a firecontrol director mounted to rotate on said platform about an axisparallel to the train axis of the gun, said director including: meansfor determining the direction of a target from the intersection of saidtrain and elevation axes; and means for simultaneously determining theinclination of the platform to the horizontal 23 in the vertical planethrough said intersection and target, the inclination of the platform tothe horizontal in a plane passing through said intersection andperpendicular to said platform and to said vertical planel :at at allinclinations of said platform in said vertical plane, and theinclination of the platform to the horizontal in the vertical plane offire of the gun at all angles of deiection of the gun relative to thefirst named plane. :sa 17. In a continuous aim lire control system, anunstable platform, a support rotatable on said platform about an axisperpendicular thereto, an outer gimbal ring mounted to rotate on saidsupport about an axis au parallel to said platform, an inner ringmounted to rotate in the outer ring about an axis perpendicular to theaxis of rotation of the outer ring, a target telescope mounted to rotateon said inner ring about an axis parallel to the axis of rotation of theinner ring in the outer ring, two telescopes arranged at a substantialangle to each other on the inner ring with their lines of sight parallelto the plane of said inner ring, and means controlled "0 by themovements of the. target telescope while held trained on a target at anylocation in space and by holding the two telescopes trained on thehorizon or distant objects to correct all of the trunnion tilt errors inthe D" train and elevation settings of a gun mounted to rotate abouttrain and elevation axes on said platform.

In testimony whereof I aix my signature.

JOSEPH DUGAN.

